Urinary catheters are frequently used in many different areas of hospitals from Intensive Care Units to Labor and Delivery. Hospitals implement sterile protocols specific to urinary catheters to reduce the risk that a patient will develop a hospital-acquired and catheter-associated urinary tract infection. However, CAUTI's remain a significant and costly type of hospital acquired infection (“HAI”) and the reasons for CAUTI's are thought to be multifactorial, including patient risk factors, nursing behaviors, data analysis, daily surveillance, catheter materials, and cleansing products.
According to an article written by Dr. Evelyn Lo, M.D. and others entitled “Strategies to Prevent Catheter-Associated Urinary Tract Infections in Acute Care Hospitals,” published in the October 2008 issue of the magazine Infection Control and Hospital Epidemiology by The University of Chicago Press, page S41, urinary tract infections are the most common of all hospital acquired infections, and 80% of urinary tract infections are attributable to indwelling urethral catheters. The January 2002 issue of the same magazine, in an article by Paul A. Tambyah, MBBS and others entitled “The Direct Costs of Nosocomial Catheter-Associated Urinary Tract Infection in the Era of Managed Care” reports at page 27 that, regardless of the sterile protocols developed for catheter use, CAUTI's still account for more than one million infections in U.S. hospitals each year. Those one million infections result in approximately 13,000 deaths a year from urinary tract infections, according to the Centers for Disease Control as reported in their Device-associated Module CAUTI, published in January 2014. Urinary catheters are not only associated with mortality due to CAUTI's, but urinary catheters are also associated with other negative outcomes including nonbacterial urethral inflammation, urethral strictures, medical trauma, morbidity, longer hospital stays, and increased antibiotic use.
Up to half of patients that require the use of an indwelling urethral catheter for five days or longer will develop bacteriuria or candiduria, as reported in “The Direct Costs of Nosocomial Catheter-Associated Urinary Tract Infection in the Era of Managed Care,” which was published by The University of Chicago Press in the January 2002 issue of Infection Control and Hospital Epidemiology. Candiduria is commonly thought of as a yeast infection. Bacteriuria is the presence of bacteria in the urine that is not associated with urine sample collection. There is a significant danger posed to hospitals by CAUTI's attributed to the presence of bacteriuria because bacteriuria may include a large reservoir of antibiotic-resistant organisms including yeasts, methicillin-resistant staphylococcus aureus, vancomycin-resistant enterococci, and multi-resistant, extended spectrum beta-lactamase-producing gram-negative bacteria.
CAUTI's not only produce negative health outcomes for patients, but result in large financial costs on the order of thirty billion dollars annually according to the non-profit Committee to Reduce Infection Deaths in the web-based article “What is RID?” 2013 available from the world wide web at the file “objective” for the site entitled “hospitalinfection” and having the top level domain name “.org” and the file extension SHTML. As more bacteria and other microorganisms become drug-resistant, the human and financial costs can be expected to increase. Hospitals may be expected to bear the expense alone or to use cost shifting or other means to pass this cost along to patients as an uninsured additional cost. As of 2008, the Centers for Medicare and Medicaid Services stopped reimbursing hospitals for the additional costs of care for patients who develop CAUTI's during hospitalization, in part as an incentive to implement steps to reduce the cost of care.
Given the severity of the problem with CAUTI's from both the human and economic loss perspectives, methods and devices have been developed to try to reduce and to combat CAUTI's. Practice in the field has focused on three areas: 1) treating the area of insertion, typically before insertion, with an antiseptic, typically an aqueous solution of povidone and iodine solution, usually a 10% solution and most commonly one of the BETADINE® brand antiseptic povidone/iodine formulations; 2) treating the catheter device, which includes making the catheter out of antimicrobial materials or applying antimicrobial or antiseptic substances to the interior or exterior surface of the catheter, including, for example one of the BETADINE® brand antiseptic povidone/iodine formulations, and 3) treating the bladder and bladder contents to prevent or reduce CAUTI's, typically with antimicrobial compounds, including taurolidine.
Maintenance of the urethral catheter presents unique issues at least in part due to the nature of the surrounding tissues, which includes the more delicate skin of the perineum, urinary meatus, and contiguous mucosa. Hospitals typically employ a sterile procedure for catheter insertion, which includes wiping down the catheter and pre-treating the area where the urethral catheter is to be inserted with an antiseptic compound, usually a povidone-iodine solution such as one of the BETADINE® brand antiseptic povidone/iodine formulations. The 2009 Guidelines for Prevention of Catheter-Associated Urinary Tract Infections published by the Centers for Disease Control (“CDC”) specifically notes that there is no documented benefit of antiseptic cleaning regimens before or after catheterization to prevent CAUTI's, as compared to sterile water. Given the high rate of CAUTI's that occur in U.S. hospitals, the common sterile procedures that use antiseptics appear to do little to reduce infection rates as compared to water.
Problems arise in part due to the nature of hospital and emergency room practice. Emergency room procedures are rarely done under ideal conditions, but can influence outcomes much later in a patient's hospital stay. A focus on the immediate, life-sustaining needs of a patient may preclude consideration of longer-term consequences. The pace of emergency room care can result in shortcuts being taken by precluding taking the time to fully follow a recommended protocol before more urgent matters are addressed. For example, incoming patients may already have a urinary tract infection (“UTI”) on arrival and under ideal conditions a protocol would be followed to confirm an existing UTI. Sometimes this step is skipped. BETADINE® brand antiseptic povidone/iodine formulations should be allowed to dry for three minutes, which may be too long in an emergency situation, resulting in poor aseptic technique when inserting a catheter. Some patients may not even need a catheter, at least not immediately, and other options may be available for urination. The tendency to catheterize emergency room patients can be further complicated by use of an inappropriate size catheter, rushing to insert the catheter, poor catheter placement, and other factors. Individual intensive care units may have widely varying CAUTI rates as a result and the rates may fluctuate. Increased rates of CAUTI's tend to come in clusters.
Another technique for reducing the opportunity for infection has been to make the catheter body out of antimicrobial materials or to coat the catheters with an antimicrobial substance, including for example, silver. On page 39 of the studies cited by the CDC Guidelines referenced above, silver alloy-coated Foley catheters reduced the risk of asymptomatic bacteriuria compared to a standard latex catheter. The results were more pronounced when the silver coated catheter was indwelling in patients that had to be catheterized for less than one week. However, using a catheter for such a short time frame may not be a viable option for all patients. The 2009 CDC Guidelines refer to “low or very low quality evidence” that suggests a benefit in using an antimicrobial or antiseptic-impregnated Foley catheter and recommends further research.
Once the catheter is inserted, another treatment method proposes that infections can be treated by irrigating the catheter with an antimicrobial compound, or instilling the bladder with the antimicrobial compound through the catheter. Some of the suggested methods use taurolidine, which has antimicrobial properties and can decrease infection rates, but produces intense pain in most tissues at concentrations as low as about 10 mg/ml. Taurolidine is not generally considered a viable option for patients that are conscious during treatment.
The Infectious Disease Society of America published in March of 2009 guidelines for the diagnosis, prevention, and treatment of Catheter-Associated Urinary Tract Infection in adults that discourages routine catheter irrigation with antimicrobials for the purpose of controlling CAUTI's in patients with indwelling catheters. The Guidelines on page 628 note that the data are said to be insufficient to recommend bladder irrigation to reduce CAUTI's. The CDC makes a similar recommendation in their 2009 Guidelines, mentioned above.
Cleansing compounds are problematic for reducing CAUTI's. Many commonly used cleansing compounds are too harsh for the delicate perineal skin, urinary meatus, and mucosa surrounding the insertion site. Generally speaking, antiseptic compounds, including povidone-iodine solution, alcohol, and chlorohexadrine, among others, and even soap and water, are somewhat harsh and their use can be problematic. Alcohol and chlorohexadrine are not recommended for use on delicate mucosa or on the perineum. Although most all of these compounds are capable of reducing potential contaminants, these compounds may actually contribute to subsequent infections by drying the skin or establishing a basic pH, whereas normal skin has a somewhat acidic pH and moisture content that serves a barrier function by limiting growth of microorganisms. Basic pH is believed to promote the growth of microorganisms, particularly when the antimicrobial ingredients have been reduced in effectiveness over time. Stripping the skin of its naturally occurring and protective lipids is believed to create chemical micro-abrasions and cause moisture loss through the epidermis, drying the skin. Contaminants may more readily enter dry, torn skin and cause infection under these conditions. Specialty lotions may be applied to restore the skin, but normally are not as effective as healthy skin.
Despite current methods and devices for reducing CAUTI's, the number of infections and the costs of treatment remain high and problematic for patients and hospitals. The multifactorial nature of the CAUTI problem makes resolution difficult. Still, it would be desirable to develop improved methods for reducing CAUTI's to more manageable levels, which improved methods are less troublesome and more efficient for hospital personnel to accept and implement compared to existing protocols and that are more readily accepted by patients.